Family of multi-speed transmission mechanisms having three planetary gear sets and six torque-transmitting devices

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets with two brakes, four clutches and three fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to at least one member of the planetary gear arrangement and an output member that is continuously connected with another of the planetary gear members. The two brakes and four clutches provide interconnections between various gear members and with the transmission housing, the input or output shaft, and the three fixed interconnections, and are operated in combinations of two to establish at least seven forward speed ratios.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a family of power transmissionshaving three planetary gear sets that are controlled by sixtorque-transmitting devices to provide at least seven forward speedratios and one reverse speed ratio.

[0003] 2. Background Art

[0004] Passenger vehicles include a powertrain that is comprised of anengine, multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted (countershafttransmissions) were the most popular.

[0005] With the advent of three- and four-speed automatic transmissions,the automatic shifting (planetary gear) transmission increased inpopularity with the motoring public. These transmissions improved theoperating performance and fuel economy of the vehicle. The increasednumber of speed ratios reduces the step size between ratios andtherefore improves the shift quality of the transmission by making theratio interchanges substantially imperceptible to the operator undernormal vehicle acceleration.

[0006] It has been suggested that the number of forward speed ratios beincreased to five, six and seven. Six-speed transmissions are disclosedin U.S. Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat.No. 6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No.5,106,352 issued to Lepelletier on Apr. 21, 1992; U.S. Pat. No.5,599,251 issued to Beim and McCarrick on Feb. 4, 1997; and U.S. Pat.Nos. 6,146,305; 6,165,097; 6,165,098; 6,174,256; and 6,193,626 issued toHebbale, Raghavan and Usoro on Nov. 14, 2000; Dec. 26, 2000; Dec. 26,2000; Jan. 16, 2001; and Feb. 27, 2001, respectively.

[0007] Six-speed transmissions offer several advantages over four- andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissions,such as Polak, having six or more forward gear ratios, passenger carsare still manufactured with three- and four-speed automatictransmissions and relatively few five or six-speed devices due to thesize and complexity of these transmissions. The Polak transmissionprovides six forward speed ratios with three planetary gear sets, twoclutches, and three brakes. The Koivunen and Beim patents utilize sixtorque-transmitting devices including four brakes and two clutches toestablish six forward speed ratios and a reverse ratio. The Lepelletierpatent employs three planetary gear sets, three clutches and two brakesto provide six forward speeds. One of the planetary gear sets ispositioned and operated to establish two fixed speed input members forthe remaining two planetary gear sets.

[0008] Seven-speed transmissions are disclosed in U.S. Pat. Nos.4,709,594 to Maeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and6,083,135 to Baldwin et. al. In addition to further improvements inacceleration and fuel economy, seven-and eight-speed transmissionsprovide an attractive marketing feature. However, like the six-speedtransmissions discussed above, the development of seven- and eight-speedtransmissions has been precluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide an improvedfamily of transmissions having three planetary gear sets controlled toprovide at least seven forward speed ratios.

[0010] In one aspect of the present invention, the family oftransmissions has three planetary gear sets, each of which includes afirst, second and third member, which members may comprise a sun gear, aring gear, or a planet carrier assembly member.

[0011] In another aspect of the present invention, each of the planetarygear sets may be of the single pinion-type or of the double pinion-type.

[0012] In yet another aspect of the present invention, the first memberof the first planetary gear set is continuously interconnected to thefirst member of the second planetary gear set through a firstinterconnecting member.

[0013] In still another aspect of the invention, a secondinterconnecting member continuously interconnects the second member ofthe first planetary gear set with the first member of the thirdplanetary gear set.

[0014] In yet another aspect of the invention, a third interconnectingmember continuously interconnects the second member of the secondplanetary gear set with the second member of the third planetary gearset.

[0015] In yet a further aspect of the invention, each family memberincorporates an input shaft which is continuously interconnected with atleast one member of the planetary gear sets and an output shaft which iscontinuously connected with another member of the planetary gear sets.

[0016] In still a further aspect of the invention, a firsttorque-transmitting mechanism, such as a brake, selectivelyinterconnects the stationary transmission housing with a member of thefirst or second planetary gear sets, or with one of the first, second,and third interconnecting members.

[0017] In another aspect of the invention, a second torque-transmittingmechanism, such as a brake, selectively interconnects the stationarytransmission housing with a member of the first, second or thirdplanetary gear sets.

[0018] In a still further aspect of the invention, a thirdtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the first planetary gear set or one of thefirst, second and third interconnecting members with the input shaft,the output shaft, or a member of the second or third planetary gearsets.

[0019] In a still further aspect of the invention, a fourthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the second planetary gear set or one of thefirst, second and third interconnecting members with the input shaft,the output shaft, or a member of the first or third planetary gear sets.

[0020] In a still further aspect of the invention, a fifthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the third planetary gear set with anothermember of the first, second and third planetary gear sets.

[0021] In still another aspect of the invention, a sixthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the first, second or third planetary gear setswith another member of the first, second or third planetary gear sets.

[0022] In still another aspect of the invention, the sixtorque-transmitting mechanisms are selectively engageable incombinations of two to yield at least seven forward speed ratios and onereverse speed ratio.

[0023] The above object and other objects, features, and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

[0025]FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

[0026]FIG. 2a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0027]FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

[0028]FIG. 3a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0029]FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

[0030]FIG. 4a is a schematic representation of a powertrain having a 5planetary transmission incorporating another family member of thepresent invention;

[0031]FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a; 10

[0032]FIG. 5a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0033]FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

[0034]FIG. 6a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0035]FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

[0036]FIG. 7a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0037]FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

[0038]FIG. 8a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0039]FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

[0040]FIG. 9a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0041]FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

[0042]FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0043]FIG. 10b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 10a;

[0044]FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0045]FIG. 11b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 11a;

[0046]FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0047]FIG. 12b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 12a;

[0048]FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0049]FIG. 13b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 13a;

[0050]FIG. 14a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0051]FIG. 14b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 14a;

[0052]FIG. 15a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0053]FIG. 15b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 15a;

[0054]FIG. 16a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0055]FIG. 16b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 16a;

[0056]FIG. 17a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

[0057]FIG. 17b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 17a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] Referring to the drawings, wherein like characters represent thesame or corresponding parts throughout the several views, there is shownin FIG. 1a a powertrain 10 having a conventional engine and torqueconverter 12, a planetary transmission 14, and a conventional finaldrive mechanism 16.

[0059] The planetary transmission 14 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 18, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 18 includes three planetary gear sets 20, 30 and 40.

[0060] The planetary gear set 20 includes a sun gear member 22, a ringgear member 24, and a planet carrier assembly 26. The planet carrierassembly 26 includes a plurality of pinion gears 27 rotatably mounted ona carrier member 29 and disposed in meshing relationship with both thesun gear member 22 and the ring gear member 24.

[0061] The planetary gear set 30 includes a sun gear member 32, a ringgear member 34, and a planet carrier assembly member 36. The planetcarrier assembly member 36 includes a plurality of pinion gears 37rotatably mounted on a carrier member 39 and disposed in meshingrelationship with both the sun gear member 32 and the ring gear member34.

[0062] The planetary gear set 40 includes a sun gear member 42, a ringgear member 44, and a planet carrier assembly member 46. The planetcarrier assembly member 46 includes a plurality of pinion gears 47rotatably mounted on a carrier member 49 and disposed in meshingrelationship with both the sun gear member 42 and the ring gear member44.

[0063] The planetary gear arrangement also includes sixtorque-transmitting mechanisms 50, 52, 54, 56, 58 and 59. Thetorque-transmitting mechanisms 50 and 52 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 54, 56, 58 and 59 are ofthe rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0064] The input shaft 17 is continuously connected with the planetcarrier assembly member 36, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 46. The sun gearmember 22 is continuously connected with the sun gear member 32 throughthe interconnecting member 70. The ring gear member 24 is continuouslyconnected with the planet carrier assembly member 46 through theinterconnecting member 72. The ring gear member 34 is continuouslyconnected with the sun gear member 42 through the interconnecting member74.

[0065] The sun gear member 22 is selectively connectable with thetransmission housing 60 through the brake 50. The ring gear member 44 isselectively connectable with the transmission housing 60 through thebrake 52. The planet carrier assembly member 36 is selectivelyconnectable with the sun gear member 32 through the clutch 54. Theplanet carrier assembly member 26 is selectively connectable with theplanet carrier assembly member 36 through the clutch 56. The planetcarrier assembly member 26 is selectively connectable with the ring gearmember 34 through the clutch 58. The planet carrier assembly member 26is selectively connectable with the ring gear member 44 through theclutch 59.

[0066] As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of two to provide eight forward speed ratios and a reversespeed ratio. It should also be noted in the truth table that thetorque-transmitting mechanism 52 remains engaged through a neutralcondition, thereby simplifying the forward/reverse interchange.

[0067] The reverse speed ratio is established with the engagement of thebrake 52 and the clutch 56. The brake 52 connects the ring gear member44 to the transmission housing 60, and the clutch 56 connects the planetcarrier assembly member 26 to the planet carrier assembly member 36. Thesun gear member 22 rotates at the same speed as the sun gear member 32.The planet carrier assembly members 26 and 36 rotate at the same speedas the input shaft 17. The ring gear member 24 rotates at the same speedas the planet carrier assembly member 46 of the output shaft 19. Thering gear member 24 rotates at a speed determined from the speed of theplanet carrier assembly member 26, the speed of the sun gear member 22,and the ring gear/sun gear tooth ratio of the planetary gear set 20. Thering gear member 34 rotates at the same speed as the sun gear member 42.The ring gear member 34 rotates at a speed determined from the speed ofthe planet carrier assembly member 36, the speed of the sun gear member32, and the ring gear/sun gear tooth ratio of the planetary gear set 30.The ring gear member 44 does not rotate. The planet carrier assemblymember 46 rotates at a speed determined from the speed of the sun gearmember 42 and the ring gear/sun gear tooth ratio of the planetary gearset 40. The numerical value of the reverse speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets20, 30 and 40.

[0068] The first forward speed ratio is established with the engagementof the brake 52 and the clutch 58. The brake 52 connects the ring gearmember 44 to the transmission housing 60, and the clutch 58 connects theplanet carrier assembly member 26 to the ring gear member 34. The sungear member 22 rotates at the same speed as the sun gear member 32. Theplanet carrier assembly member 26 rotates at the same speed as the ringgear member 34 and the sun gear member 42. The ring gear member 24rotates at the same speed as the planet carrier assembly member 46 andthe output shaft 19. The planet carrier assembly member 26 rotates at aspeed determined from the speed of the ring gear member 24, the speed ofthe sun gear member 22, and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The planet carrier assembly member 36 rotates atthe same speed as the input shaft 17. The ring gear member 34 rotates ata speed determined from the speed of the planet carrier assembly member36, the speed of the sun gear member 32, and the ring gear/sun geartooth ratio of the planetary gear set 30. The ring gear member 44 doesnot rotate. The planet carrier assembly member 46, and therefore theoutput shaft 19, rotates at a speed determined from the speed of the sungear member 42 and the ring gear/sun gear tooth ratio of the planetarygear set 40. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20, 30 and 40.

[0069] The second forward speed ratio is established with the engagementof the brake 52 and the clutch 54. The brake 52 connects the ring gearmember 44 to the transmission housing 60, and the clutch 54 connects thesun gear member 22 to the planet carrier assembly member 36. The sungear members 22,32 and the planet carrier assembly member 36 rotate atthe same speed as the input shaft 17. The ring gear member 24 rotates atthe same speed as the planet carrier assembly member 46 and the outputshaft 19. The ring gear member 34 rotates at the same speed as the sungear member 42. The planet carrier assembly member 46, and therefore theoutput shaft 19, rotates at a speed determined from the speed of the sungear member 42 and the ring gear/sun gear tooth ratio of the planetarygear set 40. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 40.

[0070] The third forward speed ratio is established with the engagementof the brakes 50 and 52. The brake 50 connects the sun gear member 22 tothe transmission housing 60, and the brake 52 connects the ring gearmember 44 to the transmission housing 60. The sun gear members 22 and 32do not rotate. The ring gear member 24 rotates at the same speed as theplanet carrier assembly member 46 and the output shaft 19. The planetcarrier assembly member 36 rotates at the same speed as the input shaft17. The ring gear member 34 rotates at the same speed as the sun gearmember 42. The ring gear member 34 rotates at a speed determined fromthe speed of the planet carrier assembly member 36 and the ring gear/sungear tooth ratio of the planetary gear set 30. The planet carrierassembly member 46, and therefore the output shaft 19, rotates at aspeed determined from the speed of the sun gear member 42 and the ringgear/sun gear tooth ratio of the planetary gear set 40. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 30 and 40.

[0071] The fourth forward speed ratio is established with the engagementof the brake 52 and the clutch 59. The brake 52 connects the ring gearmember 44 to the transmission housing 60, and the clutch 59 connects theplanet carrier assembly member 26 to the ring gear member 44. The planetcarrier assembly member 26 and ring gear member 44 do not rotate. Thesun gear member 22 rotates at the same speed as the sun gear member 32.The ring gear member 24 rotates at the same speed as the planet carrierassembly member 46 and the output shaft 19. The ring gear member 24rotates at a speed determined from the speed of the sun gear member 22and the ring gear/sun gear tooth ratio of the planetary gear set 20. Theplanet carrier assembly member 36 rotates at the same speed as the inputshaft 17. The ring gear member 34 rotates at the same speed as the sungear member 42. The ring gear member 34 rotates at a speed determinedfrom the speed of the planet carrier assembly member 36, the speed ofthe sun gear member 32, and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The planet carrier assembly member 46, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the sun gear member 42 and the ring gear/sun gear tooth ratioof the planetary gear set 40. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 20, 30 and 40.

[0072] The fifth forward speed ratio is established with the engagementof the brake 50 and the clutch 59. The brake 50 connects the sun gearmember 22 to the transmission housing 60, and the clutch 59 connects theplanet carrier assembly member 26 to the ring gear member 44. The sungear members 22 and 32 do not rotate. The planet carrier assembly member26 rotates at the same speed as the ring gear member 44. The ring gearmember 24 rotates at the same speed as the planet carrier assemblymember 46 and the output shaft 19. The planet carrier assembly member 26rotates at a speed determined from the speed of the ring gear member 24and the ring gear/sun gear tooth ratio of the planetary gear set 20. Theplanet carrier assembly member 36 rotates at the same speed as the inputshaft 17. The ring gear member 34 rotates at the same speed as the sungear member 42. The ring gear member 34 rotates at a speed determinedfrom the speed of the planet carrier assembly member 36 and the ringgear/sun gear tooth ratio of the planetary gear set 30. The planetcarrier assembly member 46, and therefore the output shaft 19, rotatesat a speed determined from the speed of the ring gear member 44, thespeed of the sun gear member 42, and the ring gear/sun gear tooth ratioof the planetary gear set 40. The numerical value of the fifth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 20, 30 and 40.

[0073] The sixth forward speed ratio is established with the engagementof the clutches 56 and 59. In this configuration, the input shaft 17 isdirectly connected with the output shaft 19. The numerical value of thesixth forward speed ratio is 1.

[0074] The seventh forward speed ratio is established with theengagement of the brake 50 and the clutch 56. The brake 50 connects thesun gear member 22 to the transmission housing 60, and the clutch 56connects the planet carrier assembly member 26 to the planet carrierassembly member 36. The sun gear members 22 and 32 do not rotate. Theplanet carrier assembly members 26 and 36 rotate at the same speed asthe input shaft 17. The ring gear member 24 and planet carrier assemblymember 46 rotate at the same speed as the output shaft 19. The ring gearmember 24 rotates at a speed determined from the speed of the planetcarrier assembly member 26 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The ring gear member 34 rotates at the same speedas the sun gear member 42. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear set 20.

[0075] The eighth forward speed ratio is established with the engagementof the brake 50 and the clutch 58. The brake 50 connects the sun gearmember 22 to the transmission housing 60, and the clutch 58 connects theplanet carrier assembly member 26 to the ring gear member 34. The sungear members 22 and 32 do not rotate. The planet carrier assembly member26 rotates at the same speed as the ring gear member 34 and the sun gearmember 42. The ring gear member 24 rotates at the same speed as theplanet carrier assembly member 46 and the output shaft 19. The ring gearmember 24 rotates at a speed determined from the speed of the planetcarrier assembly member 26 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The planet carrier assembly member 36 rotates atthe same speed as the input shaft 17. The ring gear member 34 rotates ata speed determined from the speed of the planet carrier assembly member36 and the ring gear/sun gear tooth ratio of the planetary gear set 30.The numerical value of the eighth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets20 and 30.

[0076] As set forth above, the engagement schedules for thetorque-transmitting mechanisms is shown in the truth table of FIG. 1b.This truth table also provides an example of speed ratios that areavailable utilizing the ring gear/sun gear tooth ratios given by way ofexample in FIG. 1b. The R1/S1 value is the tooth ratio of the planetarygear set 20; the R2/S2 value is the tooth ratio of the planetary gearset 30; and the R3/S3 value is the tooth ratio of the planetary gear set40. Also, the chart of FIG. 1b describes the ratio steps that areattained utilizing the sample of tooth ratios given. For example, thestep ratio between the first and second forward speed ratios is 1.72,while the step ratio between the reverse and first forward ratio is−0.82. It can also be readily determined from the truth table of FIG. 1bthat all of the single step forward ratio interchanges are of the singletransition variety, as are the double step forward ratio interchanges.

[0077]FIG. 2a shows a powertrain 110 having a conventional engine andtorque converter 12, a planetary transmission 114, and a conventionalfinal drive mechanism 16.

[0078] The planetary transmission 114 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 118, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 118 includes three planetary gear sets 120, 130 and 140.

[0079] The planetary gear set 120 includes a sun gear member 122, a ringgear member 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

[0080] The planetary gear set 130 includes a sun gear member 132, a ringgear member 134, and a planet carrier assembly member 136. The planetcarrier assembly member 136 includes a plurality of pinion gears 137rotatably mounted on a carrier member 139 and disposed in meshingrelationship with both the sun gear member 132 and the ring gear member134.

[0081] The planetary gear set 140 includes a sun gear member 142, a ringgear member 144, and a planet carrier assembly member 146. The planetcarrier assembly member 146 includes a plurality of pinion gears 147rotatably mounted on a carrier member 149 and disposed in meshingrelationship with both the sun gear member 142 and the ring gear member144.

[0082] The planetary gear arrangement 118 also includes sixtorque-transmitting mechanisms 150, 152, 154, 156, 158 and 159. Thetorque-transmitting mechanisms 150 and 152 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 154, 156, 158 and 159 areof the rotating-type torque-transmitting mechanisms, commonly termed“clutches.”

[0083] The input shaft 17 is continuously connected with the planetcarrier assembly member 146, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 126. The planetcarrier assembly member 126 is continuously connected with the ring gearmember 134 through the interconnecting member 170. The sun gear member122 is continuously connected with the ring gear member 144 through theinterconnecting member 172. The sun gear member 132 is continuouslyconnected with the sun gear member 142 through the interconnectingmember 174.

[0084] The ring gear member 124 is selectively connectable with thetransmission housing 160 through the brake 150. The sun gear member 132is selectively connectable with the transmission housing 160 through thebrake 152. The sun gear member 122 is selectively connectable with theplanet carrier assembly member 136 through the clutch 154. The ring gearmember 124 is selectively connectable with the planet carrier assemblymember 136 through the clutch 156. The planet carrier assembly member136 is selectively connectable with the planet carrier assembly member146 through the clutch 158. The planet carrier assembly member 146 isselectively connectable with the sun gear member 142 through the clutch159.

[0085] The truth table of FIG. 2b describes the engagement sequenceutilized to provide eight forward speed ratios and a reverse speed ratioin the planetary gear arrangement 118 shown in FIG. 2a.

[0086] The reverse speed ratio is established with the engagement of thebrake 150 and the clutch 158. The brake 150 connects the ring gearmember 124 to the transmission housing 160, and the clutch 158 connectsthe planet carrier assembly member 136 to the planet carrier assemblymember 146. The ring gear member 124 does not rotate. The planet carrierassembly member 126 rotates at the same speed as the ring gear member134 and the output shaft 19. The sun gear member 122 rotates at the samespeed as the ring gear member 144. The planet carrier assembly member126 rotates at a speed determined from the speed of the sun gear member122 and the ring gear/sun gear tooth ratio of the planetary gear set120. The planet carrier assembly members 136 and 146 rotate at the samespeed as the input shaft 17. The sun gear members 132 and 142 rotate atthe same speed. The sun gear member 132 rotates at a speed determinedfrom the speed of the ring gear member 134, the speed of the planetcarrier assembly member 136, and the ring gear/sun gear tooth ratio ofthe planetary gear set 130. The ring gear member 144 rotates at a speeddetermined from the speed of the planet carrier assembly member 146, thespeed of the sun gear member 142, and the ring gear/sun gear tooth ratioof the planetary gear set 140. The numerical value of the reverse speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

[0087] The first forward speed ratio is established with the engagementof the brake 150 and the clutch 154. The brake 150 connects the ringgear member 124 to the transmission housing 160, and the clutch 154connects the sun gear member 122 to the planet carrier assembly member136. The ring gear member 124 does not rotate. The planet carrierassembly member 126 rotates at the same speed as the ring gear member134 and the output shaft 19. The sun gear member 122 rotates at the samespeed as the planet carrier assembly member 136 and the ring gear member144. The planet carrier assembly member 126 rotates at a speeddetermined from the speed of the sun gear member 122 and the ringgear/sun gear tooth ratio of the planetary gear set 120. The sun gearmembers 132 and 142 rotate at the same speed. The planet carrierassembly member 136 rotates at a speed determined from the speed of thering gear member 134, the speed of the sun gear member 132, and the ringgear/sun gear tooth ratio of the planetary gear set 130. The planetcarrier assembly member 146 rotates at the same speed as the input shaft17. The ring gear member 144 rotates at a speed determined from thespeed of the planet carrier assembly member 146, the speed of the sungear member 142, and the ring gear/sun gear tooth ratio of the planetarygear set 140. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

[0088] The second forward speed ratio is established with the engagementof the brake 150 and the clutch 159. The brake 150 connects the ringgear member 124 to the transmission housing 160, and the clutch 159connects the planet carrier assembly member 146 to the sun gear member142. The ring gear member 124 does not rotate. The planet carrierassembly member 126 rotates at the same speed as the ring gear member134 and the output shaft 19. The sun gear member 122 rotates at the samespeed as the ring gear member 144. The planet carrier assembly member126 rotates at a speed determined from the speed of the sun gear member122 and the ring gear/sun gear tooth ratio of the planetary gear set120. The sun gear members 132 and 142, and the planet carrier assemblymember 146 rotate at the same speed as the input shaft 17. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 120.

[0089] The third forward speed ratio is established with the engagementof the brakes 150 and 152. The brake 150 connects the ring gear member124 to the transmission housing 160, and the brake 152 connects the sungear member 132 to the transmission housing 160. The ring gear member124 does not rotate. The planet carrier assembly member 126 rotates atthe same speed as the ring gear member 134 and the output shaft 19. Thesun gear member 122 rotates at the same speed as the ring gear member144. The planet carrier assembly member 126 rotates at a speeddetermined from the speed of the sun gear member 122 and the ringgear/sun gear tooth ratio of the planetary gear set 120. The sun gearmembers 132 and 142 do not rotate. The planet carrier assembly member146 rotates at the same speed as the input shaft 17. The ring gearmember 144 rotates at a speed determined from the speed of the planetcarrier assembly member 146 and the ring gear/sun gear tooth ratio ofthe planetary gear set 140. The numerical value of the third forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 120 and 140.

[0090] The fourth forward speed ratio is established with the engagementof the brake 150 and the clutch 156. The brake 150 connects the ringgear member 124 to the transmission housing 160, and the clutch 156connects the ring gear member 124 to the planet carrier assembly member136. The ring gear member 124 and planet carrier assembly member 136 donot rotate. The planet carrier assembly member 126 and ring gear member134 rotate at the same speed as the output shaft 19. The sun gear member122 rotates at the same speed as the ring gear member 144. The planetcarrier assembly member 126 rotates at a speed determined from the speedof the sun gear member 122 and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The sun gear members 132 and 142 rotate at thesame speed. The sun gear member 132 rotates at a speed determined fromthe speed of the ring gear member 134 and the ring gear/sun gear toothratio of the planetary gear set 130. The planet carrier assembly member146 rotates at the same speed as the input shaft 17. The ring gearmember 144 rotates at a speed determined from the speed of the planetcarrier assembly member 146, the speed of the sun gear member 142, andthe ring gear/sun gear tooth ratio of the planetary gear set 140. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets120, 130 and 140.

[0091] The fifth forward speed ratio is established with the engagementof the brake 152 and the clutch 156. The brake 152 connects the sun gearmember 132 to the transmission housing 160, and the clutch 156 connectsthe ring gear member 124 to the planet carrier assembly member 136. Thering gear member 124 rotates at the same speed as the planet carrierassembly member 136. The planet carrier assembly member 126 rotates atthe same speed as the ring gear member 134 and the output shaft 19. Thesun gear member 122 rotates at the same speed as the ring gear member144. The planet carrier assembly member 126 rotates at a speeddetermined from the speed of the ring gear member 124, the speed of thesun gear member 122, and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The sun gear members 132 and 142 do not rotate.The planet carrier assembly member 136 rotates at a speed determinedfrom the speed of the ring gear member 134 and the ring gear/sun geartooth ratio of the planetary gear set 130. The planet carrier assemblymember 146 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 146 rotates at a speed determined from the speedof the ring gear member 144 and the ring gear/sun gear tooth ratio ofthe planetary gear set 140. The numerical value of the fifth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 120, 130 and 140.

[0092] The sixth forward speed ratio is established with the engagementof the clutches 156 and 158. In this configuration, the input shaft 17is directly connected to the output shaft 19. The numerical value of thesixth forward speed ratio is 1.

[0093] The seventh forward speed ratio is established with theengagement of the brake 152 and the clutch 158. The brake 152 connectsthe sun gear member 132 to the transmission housing 160, and the clutch158 connects the planet carrier assembly member 136 to the planetcarrier assembly member 146. The planet carrier assembly member 126rotates at the same speed as the ring gear member 134 and the outputshaft 19. The sun gear member 122 rotates at the same speed as the ringgear member 144. The sun gear members 132 and 142 do not rotate. Theplanet carrier assembly members 136 and 146 rotate at the same speed asthe input shaft 17. The ring gear member 134 rotates at a speeddetermined from the speed of the planet carrier assembly member 136 andthe ring gear/sun gear tooth ratio of the planetary gear set 130. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set130.

[0094] The eighth forward speed ratio is established with the engagementof the brake 152 and the clutch 154. The brake 152 connects the sun gearmember 132 to the transmission housing 160, and the clutch 154 connectsthe sun gear member 122 to the planet carrier assembly member 136. Theplanet carrier assembly member 126 rotates at the same speed as the ringgear member 134 and the output shaft 19. The planet carrier assemblymember 136 rotates at the same speed as the sun gear member 122 and thering gear member 144. The sun gear members 132 and 142 do not rotate.The planet carrier assembly member 136 rotates at a speed determinedfrom the speed of the ring gear member 134 and the ring gear/sun geartooth ratio of the planetary gear set 130. The planet carrier assemblymember 146 rotates at the same speed as the input shaft 17. The ringgear member 144 rotates at a speed determined from the speed of theplanet carrier assembly member 146 and the ring gear/sun gear toothratio of the planetary gear set 140. The numerical value of the eighthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 130 and 140.

[0095] As set forth above, the truth table of FIG. 2b describes theengagement sequence of the torque-transmitting mechanisms utilized toprovide a reverse drive ratio and eight forward speed ratios. It can bereadily determined from the truth table that all of the single stepforward interchanges are of the single transition type, as are thedouble step forward interchanges. The truth table also provides anexample of the ratios that can be attained with the family members shownin FIG. 2a utilizing the sample tooth ratios given in FIG. 2b. The R1/S1value is the tooth ratio of the planetary gear set 120; the R2/S2 valueis the tooth ratio of the planetary gear set 130; and the R3/S3 value isthe tooth ratio of the planetary gear set 140. Also shown in FIG. 2b arethe ratio steps between single step ratios in the forward direction aswell as the reverse to first ratio step ratio. For example, the first tosecond step ratio is 1.79.

[0096] Turning to FIG. 3a, a powertrain 210 includes the engine andtorque converter 12, a planetary transmission 214, and a final drivemechanism 16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

[0097] The planetary gear set 220 includes a sun gear member 222, a ringgear member 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

[0098] The planetary gear set 230 includes a sun gear member 232, a ringgear member 234, and a planet carrier assembly member 236. The planetcarrier assembly member 236 includes a plurality of pinion gears 237rotatably mounted on a carrier member 239 and disposed in meshingrelationship with both the sun gear member 232 and the ring gear member234.

[0099] The planetary gear set 240 includes a sun gear member 242, a ringgear member 244, and a planet carrier assembly member 246. The planetcarrier assembly member 246 includes a plurality of pinion gears 247rotatably mounted on a carrier member 249 and disposed in meshingrelationship with both the sun gear member 242 and the ring gear member244.

[0100] The planetary gear arrangement 218 also includes sixtorque-transmitting mechanisms 250, 252, 254, 256, 258 and 259. Thetorque-transmitting mechanisms 250 and 252 are stationary typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 254, 256, 258 and 259 areof the rotating type torque-transmitting mechanisms, commonly termedclutches.

[0101] The input shaft 17 is continuously connected with the sun gearmember 242, and the output shaft 19 is continuously connected with theplanet carrier assembly member 236. The sun gear member 222 iscontinuously connected with the sun gear member 232 through theinterconnecting member 270. The ring gear member 224 is continuouslyconnected with the ring gear member 244 through the interconnectingmember 272. The ring gear member 234 is continuously connected with theplanet carrier assembly member 246 through the interconnecting member274.

[0102] The sun gear member 222 is selectively connectable with thetransmission housing 260 through the brake 250. The planet carrierassembly member 226 is selectively connectable with the transmissionhousing 260 through the brake 252. The ring gear member 244 isselectively connectable with the planet carrier assembly member 246through the clutch 254. The ring gear member 224 is selectivelyconnectable with the planet carrier assembly member 236 through theclutch 256. The planet carrier assembly member 226 is selectivelyconnectable with the planet carrier assembly member 236 through theclutch 258. The sun gear member 242 is selectively connectable with theplanet carrier assembly member 226 through the clutch 259.

[0103] As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of two to establish seven forwardspeed ratios and one reverse ratio.

[0104] The reverse speed ratio is established with the engagement of thebrake 252 and the clutch 256. The brake 252 connects the planet carrierassembly member 226 to the transmission housing 260, and the clutch 256connects the ring gear member 224 to the planet carrier assembly member236. The planet carrier assembly member 226 does not rotate. The sungear member 222 rotates at the same speed as the sun gear member 232.The ring gear member 224 rotates at the same speed as the ring gearmember 244, the planet carrier assembly member 236, and the output shaft19. The speed of the ring gear member 224 is determined from the speedof the sun gear member 222 and the ring gear/sun gear tooth ratio of theplanetary gear set 220. The ring gear member 234 rotates at the samespeed as the planet carrier assembly member 246. The planet carrierassembly member 236 rotates at a speed determined from the speed of thesun gear member 232, the speed of the ring gear member 234, and the ringgear/sun gear tooth ratio of the planetary gear set 230. The sun gearmember 242 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 246 rotates at a speed determined from the speedof the ring gear member 244, the speed of the sun gear member 242, andthe ring gear/sun gear tooth ratio of the planetary gear set 240. Thenumerical value of the reverse speed ratio is determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 220, 230 and240.

[0105] The first forward speed ratio is established with the engagementof the brake 252 and the clutch 254. The brake 252 connects the planetcarrier assembly member 226 to the transmission housing 260, and theclutch 254 connects the ring gear member 244 to the planet carrierassembly member 246. The planet carrier assembly member 226 does notrotate. The sun gear members 222 and 232 rotate at the same speed. Thering gear members 224, 234 and 244 rotate at the same speed as theplanet carrier assembly member 246. The ring gear member 224 rotates ata speed determined from the speed of the sun gear member 222 and thering gear/sun gear tooth ratio of the planetary gear set 220. The planetcarrier assembly member 236 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 236 rotates at a speeddetermined from the speed of the ring gear member 234, the speed of thesun gear member 232, and the ring gear/sun gear tooth ratio of theplanetary gear set 230. The sun gear member 242 rotates at the samespeed as the input shaft 17. The numerical value of the first forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220 and 230.

[0106] The second forward speed ratio is established with the engagementof the brakes 250 and 252. The brake 250 connects the sun gear member222 to the transmission housing 260, and the brake 252 connects theplanet carrier assembly member 226 to the transmission housing 260. Theplanetary gear set 220, sun gear member 232, and ring gear member 244 donot rotate. The ring gear member 234 rotates at the same speed as theplanet carrier assembly member 246. The planet carrier assembly member236 rotates at the same speed as the output shaft 19. The planet carrierassembly member 236 rotates at a speed determined from the speed of thering gear member 234 and the ring gear/sun gear tooth ratio of theplanetary gear set 230. The sun gear member 242 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 246rotates at a speed determined from the speed of the ring gear member244, the speed of the sun gear member 242, and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of thesecond forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 230 and 240.

[0107] The third forward speed ratio is established with the engagementof the brake 250 and the clutch 254. The brake 250 connects the sun gearmember 222 to the transmission housing 260, and the clutch 254 connectsthe ring gear member 244 to the planet carrier assembly member 246. Thesun gear members 222 and 232 do not rotate. The ring gear members 224,234 and 244 rotate at the same speed as the planet carrier assemblymember 246. The planet carrier assembly member 236 rotates at the samespeed as the output shaft 19. The speed of the planet carrier assemblymember 226 is determined from the speed of the ring gear member 234 andthe ring gear/sun gear tooth ratio of the planetary gear set 230. Thesun gear member 242 rotates at the same speed as the input shaft 17. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 230.

[0108] The fourth forward speed ratio is established with the engagementof the brake 250 and the clutch 258. The brake 250 connects the sun gearmember 222 to the transmission housing 260, and the clutch 258 connectsthe planet carrier assembly member 226 to the planet carrier assemblymember 236. The sun gear members 222 and 232 do not rotate. The ringgear members 224 and 244 rotate at the same speed. The planet carrierassembly members 226 and 236 rotate at the same speed as the outputshaft 19. The planet carrier assembly member 226 rotates at a speeddetermined from the speed of the ring gear member 224 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The ring gearmember 234 rotates at the same speed as the planet carrier assemblymember 246. The planet carrier assembly member 236 rotates at a speeddetermined from the speed of the ring gear member 234 and the ringgear/sun gear tooth ratio of the planetary gear set 230. The sun gearmember 242 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 246 rotates at a speed determined from the speedof the ring gear member 244, the speed of the sun gear member 242, andthe ring gear/sun gear tooth ratio of the planetary gear set 240. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets220, 230 and 240.

[0109] The fifth forward speed ratio is established with the engagementof the brake 250 and the clutch 256. The brake 250 connects the sun gearmember 222 to the transmission housing 260, and the clutch 256 connectsthe ring gear member 224 to the planet carrier assembly member 236. Thesun gear members 222 and 232 do not rotate. The ring gear members 224and 244 rotate at the same speed as the planet carrier assembly member236 and the output shaft 19. The ring gear member 234 rotates at thesame speed as the planet carrier assembly member 246. The planet carrierassembly member 236 rotates at a speed determined from the speed of thering gear member 234 and the ring gear/sun gear tooth ratio of theplanetary gear set 230. The sun gear member 242 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 246rotates at a speed determined from the speed of the ring gear member244, the speed of the sun gear member 242, and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of thefifth forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 230 and 240.

[0110] The sixth forward speed ratio is established with the engagementof the brake 250 and the clutch 259. The brake 250 connects the sun gearmember 222 to the transmission housing 260, and the clutch 259 connectsthe planet carrier assembly member 226 to the sun gear member 242. Thesun gear members 222 and 232 do not rotate. The planet carrier assemblymember 226 and sun gear member 242 rotate at the same speed as the inputshaft 17. The ring gear member 224 rotates at the same speed as the ringgear member 244. The planet carrier assembly member 226 rotates at aspeed determined from the speed of the ring gear member 224 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The ring gearmember 234 rotates at the same speed as the planet carrier assemblymember 246. The planet carrier assembly member 236 rotates at the samespeed as the output shaft 19. The planet carrier assembly member 236rotates at a speed determined from the speed of the ring gear member 234and the ring gear/sun gear tooth ratio of the planetary gear set 230.The planet carrier assembly member 246 rotates at a speed determinedfrom the speed of the ring gear member 244, the speed of the sun gearmember 242, and the ring gear/sun gear tooth ratio of the planetary gearset 240. The numerical value of the sixth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 220, 230 and 240.

[0111] The seventh forward speed ratio is established with theengagement of the clutches 254 and 256. In this configuration, the inputshaft 17 is directly connected to the output shaft 19. The numericalvalue of the seventh forward speed ratio is 1.

[0112] As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.52. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety, as are all of the double step forward interchanges.

[0113] A powertrain 310, shown in FIG. 4a, includes the engine andtorque converter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

[0114] The planetary gear set 320 includes a sun gear member 322, a ringgear member 324, and a planet carrier assembly member 326. The planetcarrier assembly member 326 includes a plurality of pinion gears 327rotatably mounted on a carrier member 329 and disposed in meshingrelationship with both the sun gear member 322 and the ring gear member324.

[0115] The planetary gear set 330 includes a sun gear member 332, a ringgear member 334, and a planet carrier assembly member 336. The planetcarrier assembly member 336 includes a plurality of pinion gears 337rotatably mounted on a carrier member 339 and disposed in meshingrelationship with both the sun gear member 332 and the ring gear member334.

[0116] The planetary gear set 340 includes a sun gear member 342, a ringgear member 344, and a planet carrier assembly member 346. The planetcarrier assembly member 346 includes a plurality of pinion gears 347rotatably mounted on a carrier member 349 and disposed in meshingrelationship with both the sun gear member 342 and the ring gear member344.

[0117] The planetary gear arrangement 318 also includes sixtorque-transmitting mechanisms 350, 352, 354, 356, 358 and 359. Thetorque-transmitting mechanisms 350 and 352 are stationary typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 354, 356, 358 and 359 areof the rotating type torque-transmitting mechanisms, commonly termedclutches.

[0118] The input shaft 17 is continuously connected with the ring gearmember 344, and the output shaft 19 is continuously connected with thering gear member 324. The planet carrier assembly member 326 iscontinuously connected with the sun gear member 332 through theinterconnecting member 370. The sun gear member 322 is continuouslyconnected with the sun gear member 342 through the interconnectingmember 372. The planet carrier assembly member 336 is continuouslyconnected with the ring gear member 344 through the interconnectingmember 374.

[0119] The planet carrier assembly member 326 is selectively connectablewith the transmission housing 360 through the brake 350. The ring gearmember 334 is selectively connectable with the transmission housing 360through the brake 352. The sun gear member 332 is selectivelyconnectable with the planet carrier assembly member 346 through theclutch 354. The ring gear member 324 is selectively connectable with thesun gear member 322 through the clutch 356. The ring gear member 324 isselectively connectable with the planet carrier assembly member 346through the clutch 358. The ring gear member 344 is selectivelyconnectable with the planet carrier assembly member 346 through theclutch 359.

[0120] The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10b, 11 b, 12 b, 13 b, 14 b, 15 b, 16 b and 17 b show the engagementsequences for the torque-transmitting mechanisms to provide at leastseven forward speed ratios and one reverse ratio. As shown and describedabove for the configuration in FIGS. 1a, 2 a and 3 a, those skilled inthe art will understand from the respective truth tables how the speedratios are established through the planetary gear sets identified in thewritten description.

[0121] The truth table shown in FIG. 4b describes the engagementcombination and the engagement sequence necessary to provide the reversedrive ratio and seven forward speed ratios. A sample of the numericalvalues for the ratios is also provided in the truth table of FIG. 4b.These values are determined utilizing the ring gear/sun gear toothratios also given in FIG. 4b. The R1/S1 value is the tooth ratio for theplanetary gear set 320; the R2/S2 value is the tooth ratio for theplanetary gear set 330; and the R3/S3 value is the tooth ratio for theplanetary gear set 340. Also given in FIG. 4b is a chart describing thestep ratios between the adjacent forward speed ratios and the reverse tofirst forward speed ratio. For example, the first to second forwardspeed ratio step is 1.95. It can be readily determined from the truthtable of FIG. 4b that each of the forward single step ratio interchangesis a single transition shift, as are the double step interchanges. Thechart also shows that the torque-transmitting mechanism 350 can beengaged through the neutral condition to simplify the forward/reverseinterchange.

[0122] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 320. The numerical values ofthe first and second forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 320 and 340.The numerical value of the third forward speed ratio is 1. The numericalvalues of the fourth and fifth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets320, 330 and 340. The numerical value of the sixth forward speed ratiois determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 330. The numerical value of the seventh forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 330 and 340.

[0123] A powertrain 410, shown in FIG. 5a, includes the engine andtorque converter 12, a planetary transmission 414 and the final drivemechanism 16. The planetary transmission 414 includes a planetary geararrangement 418, input shaft 17 and output shaft 19. The planetary geararrangement 418 includes three simple planetary gear sets 420, 430 and440.

[0124] The planetary gear set 420 includes a sun gear member 422, a ringgear member 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

[0125] The planetary gear set 430 includes a sun gear member 432, a ringgear member 434, and a planet carrier assembly member 436. The planetcarrier assembly member 436 includes a plurality of pinion gears 437rotatably mounted on a carrier member 439 and disposed in meshingrelationship with both the sun gear member 432 and the ring gear member434.

[0126] The planetary gear set 440 includes a sun gear member 442, a ringgear member 444, and a planet carrier assembly member 446. The planetcarrier assembly member 446 includes a plurality of pinion gears 447rotatably mounted on a carrier member 449 and disposed in meshingrelationship with both the sun gear member 442 and the ring gear member444.

[0127] The planetary gear arrangement 418 also includes sixtorque-transmitting mechanisms 450, 452, 454, 456, 458 and 459. Thetorque-transmitting mechanisms 450 and 452 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 454, 456, 458 and 459 areof the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0128] The input shaft 17 is continuously connected with the planetcarrier assembly member 426 and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 446. The sun gearmember 422 is continuously connected with the planet carrier assemblymember 436 through the interconnecting member 470. The planet carrierassembly member 426 is continuously connected with the ring gear member444 through the interconnecting member 472. The ring gear member 434 iscontinuously connected with the planet carrier assembly member 446through the interconnecting member 474.

[0129] The sun gear member 422 is selectively connectable with thetransmission housing 460 through the brake 450. The ring gear member 424is selectively connectable with the transmission housing 460 through thebrake 452. The sun gear member 432 is selectively connectable with theplanet carrier assembly member 436 through the clutch 454. The planetcarrier assembly member 436 is selectively connectable with the sun gearmember 442 through the clutch 456. The planet carrier assembly member426 is selectively connectable with the sun gear member 432 through theclutch 458. The sun gear member 432 is selectively connectable with thesun gear member 442 through the clutch 459.

[0130] The truth table shown in FIG. 5b describes the engagementcombination and sequence of the torque-transmitting mechanisms 450, 452,454, 456, 458 and 459 that are employed to provide the reverse driveratio and the seven forward speed ratios. It should be noted that thetorque-transmitting mechanism 450 is engaged through the neutralcondition to simplify the forward/reverse interchange.

[0131] Also given in the truth table of FIG. 5b is a set of numericalvalues that are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single step forward interchanges are single transitionshifts.

[0132]FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is2.02. Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 430. The numerical value ofthe first forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 430 and 440. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 440. The numericalvalue of the third forward speed ratio is 1. The numerical value of thefourth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 420 and 440. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 420, 430 and 440.The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set420. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 420 and 430.

[0133] A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

[0134] The planetary gear set 520 includes a sun gear member 522, a ringgear member 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

[0135] The planetary gear set 530 includes a sun gear member 532, a ringgear member 534, and a planet carrier assembly member 536. The planetcarrier assembly member 536 includes a plurality of pinion gears 537rotatably mounted on a carrier member 539 and disposed in meshingrelationship with both the sun gear member 532 and the ring gear member534.

[0136] The planetary gear set 540 includes a sun gear member 542, a ringgear member 544, and a planet carrier assembly member 546. The planetcarrier assembly member 546 includes a plurality of pinion gears 547rotatably mounted on a carrier member 549 and disposed in meshingrelationship with both the sun gear member 542 and the ring gear member544.

[0137] The planetary gear arrangement 518 also includes sixtorque-transmitting mechanisms 550, 552, 554, 556, 558 and 559. Thetorque-transmitting mechanisms 550 and 552 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 554, 556, 558 and 559 arerotating-type torque-transmitting mechanisms, commonly termed clutches.

[0138] The input shaft 17 is continuously connected with the planetcarrier assembly member 526, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 546. The sun gearmember 522 is continuously connected with the planet carrier assemblymember 536 through the interconnecting member 570. The planet carrierassembly member 526 is continuously connected with the ring gear member544 through the interconnecting member 572. The ring gear member 534 iscontinuously connected with the planet carrier assembly member 546through the interconnecting member 574.

[0139] The sun gear member 522 is selectively connectable with thetransmission housing 560 through the brake 550. The ring gear member 524is selectively connectable with the transmission housing 560 through thebrake 552. The planet carrier assembly member 536 is selectivelyconnectable with the ring gear member 534 through the clutch 554. Theplanet carrier assembly member 536 is selectively connectable with thesun gear member 542 through the clutch 556. The planet carrier assemblymember 526 is selectively connectable with the sun gear member 532through the clutch 558. The sun gear member 532 is selectivelyconnectable with the sun gear member 542 through the clutch 559.

[0140] The truth table shown in FIG. 6b describes the engagementsequence and combination of the torque-transmitting mechanisms toprovide the reverse speed ratio and seven forward speed ratios. Itshould be noted that the torque-transmitting mechanism 550 can remainengaged through the neutral condition, thereby simplifying theforward/reverse interchange. It can also be determined from the truthtable of FIG. 6b that all of the single step forward ratio interchangesare of the single transition variety, as are all of the double stepforward interchanges. The chart of FIG. 6b describes the ratio stepsbetween adjacent forward speed ratios and the ratio step between thereverse and first forward speed ratio.

[0141] Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 530. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 530 and 540. Thenumerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set540. The numerical value of the third forward speed ratio is 1. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets520 and 540. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 520, 530 and 540. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 520. The numerical value of the seventhforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 520 and 530.

[0142] The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

[0143] A powertrain 610, shown in FIG. 7a, has the engine and torqueconverter 12, a planetary transmission 614 and the final drive mechanism16. The planetary transmission 614 includes the input shaft 17, aplanetary gear arrangement 618 and the output shaft 19. The planetarygear arrangement 618 includes three planetary gear sets 620, 630 and640.

[0144] The planetary gear set 620 includes a sun gear member 622, a ringgear member 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

[0145] The planetary gear set 630 includes a sun gear member 632, a ringgear member 634, and a planet carrier assembly member 636. The planetcarrier assembly member 636 includes a plurality of pinion gears 637rotatably mounted on a carrier member 639 and disposed in meshingrelationship with both the sun gear member 632 and the ring gear member634.

[0146] The planetary gear set 640 includes a sun gear member 642, a ringgear member 644, and a planet carrier assembly member 646. The planetcarrier assembly member 646 includes a plurality of pinion gears 647rotatably mounted on a carrier member 649 and disposed in meshingrelationship with both the sun gear member 642 and the ring gear member644.

[0147] The planetary gear arrangement 618 also includes sixtorque-transmitting mechanisms 650, 652, 654, 656, 658 and 659. Thetorque-transmitting mechanisms 650 and 652 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 654, 656, 658 and 659 areof the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0148] The input shaft 17 is continuously connected with the planetcarrier assembly member 646, and the output shaft 19 is continuouslyconnected with the ring gear member 634. The sun gear member 622 iscontinuously connected with the sun gear member 632 through theinterconnecting member 670. The ring gear member 624 is continuouslyconnected with the planet carrier assembly member 646 through theinterconnecting member 672. The planet carrier assembly member 636 iscontinuously connected with the sun gear member 642 through theinterconnecting member 674.

[0149] The planet carrier assembly member 636 is selectively connectablewith the transmission housing 660 through the brake 650. The ring gearmember 644 is selectively connectable with the transmission housing 660through the brake 652. The ring gear member 624 is selectivelyconnectable with the sun gear member 622 through the clutch 654. The sungear member 632 is selectively connectable with the planet carrierassembly member 636 through the clutch 656. The planet carrier assemblymember 626 is selectively connectable with the ring gear member 634through the clutch 658. The planet carrier assembly member 626 isselectively connectable with the planet carrier assembly member 636through the clutch 659.

[0150] The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the reversedrive ratio and seven forward speed ratios, as well as the sequence ofthese engagements and interchanges. The torque-transmitting mechanism650 can be engaged through the neutral condition, thereby simplifyingthe forward/reverse interchange. It can be noted from the truth tablethat each of the single step forward interchanges are single transitionratio changes, as are the double step forward interchanges.

[0151] The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b.

[0152] Those skilled in the art will, upon reviewing the truth table ofFIG. 7b, recognize that the numerical value of the reverse speed ratiois determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 630. The numerical values of the first and secondforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 620 and 630. The numerical valueof the third forward speed ratio is 1. The numerical values of thefourth and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 620, 630 and 640.The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set640. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 630 and 640.

[0153] A powertrain 710, shown in FIG. 8a, has the conventional engineand torque converter 12, a planetary transmission 714, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 714 throughthe input shaft 17. The planetary transmission 714 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

[0154] The planetary gear set 720 includes a sun gear member 722, a ringgear member 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

[0155] The planetary gear set 730 includes a sun gear member 732, a ringgear member 734, and a planet carrier assembly member 736. The planetcarrier assembly member 736 includes a plurality of pinion gears 737rotatably mounted on a carrier member 739 and disposed in meshingrelationship with both the sun gear member 732 and the ring gear member734.

[0156] The planetary gear set 740 includes a sun gear member 742, a ringgear member 744, and a planet carrier assembly member 746. The planetcarrier assembly member 746 includes a plurality of pinion gears 747rotatably mounted on a carrier member 749 and disposed in meshingrelationship with both the sun gear member 742 and the ring gear member744.

[0157] The planetary gear arrangement 718 also includes sixtorque-transmitting mechanisms 750, 752, 754, 756, 758 and 759. Thetorque-transmitting mechanisms 750 and 752 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 754, 756, 758 and 759 areof the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0158] The input shaft 17 is continuously connected with the planetcarrier assembly member 746, and the output shaft 19 is continuouslyconnected with the ring gear member 734. The sun gear member 722 iscontinuously connected with the sun gear member 732 through theinterconnecting member 770. The ring gear member 724 is continuouslyconnected with the sun gear member 742 through the interconnectingmember 772. The planet carrier assembly member 736 is continuouslyconnected with the ring gear member 744 through the interconnectingmember 774.

[0159] The ring gear member 724 is selectively connectable with thetransmission housing 760 through the brake 750. The planet carrierassembly member 726 is selectively connectable with the transmissionhousing 760 through the brake 752. The planet carrier assembly member736 is selectively connectable with the sun gear member 732 through theclutch 754. The planet carrier assembly member 726 is selectivelyconnectable with the planet carrier assembly member 736 through theclutch 756. The planet carrier assembly member 726 is selectivelyconnectable with the planet carrier assembly member 746 through theclutch 758. The ring gear member 744 is selectively connectable with theplanet carrier assembly member 746 through the clutch 759.

[0160] The truth table of FIG. 8b defines the torque-transmittingmechanism engagement sequence utilized for each of the forward speedratios and the reverse speed ratio. Also given in the truth table is aset of numerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single step forwardinterchanges are single transition shifts, as are the double stepinterchanges in the forward direction.

[0161]FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is2. Those skilled in the art will recognize that the numerical values ofthe reverse, first and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets720, 730 and 740. The numerical value of the second forward speed ratiois 1. The numerical value of the third forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set740. The numerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets720 and 740. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 730 and 740. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 720 and 730.

[0162] A powertrain 810, shown in FIG. 9a, has the conventional engineand torque converter 12, a planetary transmission 814, and the finaldrive mechanism 16. The engine and torque converter 12 are drivinglyconnected with the planetary transmission 814 through the input shaft17. The planetary transmission 814 is drivingly connected with the finaldrive mechanism 16 through the output shaft 19. The planetarytransmission 814 includes a planetary gear arrangement 818 that has afirst planetary gear set 820, a second planetary gear set 830, and athird planetary gear set 840.

[0163] The planetary gear set 820 includes a sun gear member 822, a ringgear member 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

[0164] The planetary gear set 830 includes a sun gear member 832, a ringgear member 834, and a planet carrier assembly member 836. The planetcarrier assembly member 836 includes a plurality of pinion gears 837rotatably mounted on a carrier member 839 and disposed in meshingrelationship with both the sun gear member 832 and the ring gear member834.

[0165] The planetary gear set 840 includes a sun gear member 842, a ringgear member 844, and a planet carrier assembly member 846. The planetcarrier assembly member 846 includes a plurality of pinion gears 847rotatably mounted on a carrier member 849 and disposed in meshingrelationship with both the sun gear member 842 and the ring gear member844.

[0166] The planetary gear arrangement 818 also includes sixtorque-transmitting mechanisms 850, 852, 854, 856, 858 and 859. Thetorque-transmitting mechanisms 850 and 852 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 854, 856, 858 and 859 areof the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0167] The input shaft 17 is continuously connected with the planetcarrier assembly member 846, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 836. The sun gearmember 822 is continuously connected with the sun gear member 832through the interconnecting member 870. The planet carrier assemblymember 826 is continuously connected with the sun gear member 842through the interconnecting member 872. The ring gear member 834 iscontinuously connected with the planet carrier assembly member 846through the interconnecting member 874.

[0168] The planet carrier assembly member 826 is selectively connectablewith the transmission housing 860 through the brake 850. The ring gearmember 844 is selectively connectable with the transmission housing 860through the brake 852. The sun gear member 822 is selectivelyconnectable with the planet carrier assembly member 826 through theclutch 854. The planet carrier assembly member 826 is selectivelyconnectable with the planet carrier assembly member 836 through theclutch 856. The ring gear member 824 is selectively connectable with theplanet carrier assembly member 836 through the clutch 858. The ring gearmember 824 is selectively connectable with the ring gear member 834through the clutch 859.

[0169] The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides the reverse ratio and sevenforward speed ratios shown in the truth table and available with theplanetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanism 850 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. A sampleof numerical values for the individual ratios is also given in the truthtable of FIG. 9b. These numerical values have been calculated using thering gear/sun gear tooth ratios also given by way of example in FIG. 9b.The R1/S1 value is the tooth ratio of the planetary gear set 820; theR2/S2 value is the tooth ratio of the planetary gear set 830; and theR3/S3 value is the tooth ratio of the planetary gear set 840. It can bereadily recognized from the truth table that all of the single anddouble step forward interchanges are single transition ratiointerchanges. FIG. 9b also describes the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is2.

[0170] Those skilled in the art of planetary transmissions willrecognize that the numerical values of the reverse and first forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 820 and 830. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 830. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 830 and 840. The numerical values ofthe fifth and seventh forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 820, 830 and840. The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set840.

[0171] The powertrain 910, shown in FIG. 10a, includes the conventionalengine and torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

[0172] The planetary gear set 920 includes a sun gear member 922, a ringgear member 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

[0173] The planetary gear set 930 includes a sun gear member 932, a ringgear member 934, and a planet carrier assembly member 936. The planetcarrier assembly member 936 includes a plurality of pinion gears 937rotatably mounted on a carrier member 939 and disposed in meshingrelationship with both the sun gear member 932 and the ring gear member934.

[0174] The planetary gear set 940 includes a sun gear member 942, a ringgear member 944, and a planet carrier assembly member 946. The planetcarrier assembly member 946 includes a plurality of pinion gears 947rotatably mounted on a carrier member 949 and disposed in meshingrelationship with both the sun gear member 942 and the ring gear member944.

[0175] The planetary gear arrangement 918 also includes sixtorque-transmitting mechanisms 950, 952, 954, 956, 958 and 959. Thetorque-transmitting mechanisms 950 and 952 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 954, 956, 958 and 959 areof the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0176] The input shaft 17 is continuously connected with the planetcarrier assembly member 926, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 936. The sun gearmember 922 is continuously connected with the sun gear member 932through the interconnecting member 970. The ring gear member 924 iscontinuously connected with the planet carrier assembly member 946through the interconnecting member 972. The ring gear member 934 iscontinuously connected with the ring gear member 944 through theinterconnecting member 974.

[0177] The sun gear member 922 is selectively connectable with thetransmission housing 960 through the brake 950. The ring gear member 924is selectively connectable with the transmission housing 960 through thebrake 952. The sun gear member 932 is selectively connectable with thesun gear member 942 through the clutch 954. The ring gear member 944 isselectively connectable with the planet carrier assembly member 946through the clutch 956. The planet carrier assembly member 926 isselectively connectable with the sun gear member 942 through the clutch958. The planet carrier assembly member 936 is selectively connectablewith the sun gear member 942 through the clutch 959.

[0178] The truth table of FIG. 10b describes the torque-transmittingmechanism engagement sequence utilized to provide the reverse speedratio and eight forward speed ratios. The truth table also provides aset of examples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940. It can also be determined from thetruth table of FIG. 10b that each of the forward single step ratiointerchanges are of the single transition variety, as are the doublestep interchanges.

[0179] Those skilled in the art, upon reviewing the engagementcombinations, will recognize that the numerical values of the reverse,first, second, sixth, seventh and eighth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 920, 930 and 940. The numerical values of the thirdand fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 920 and 930. Thenumerical value of the fourth forward speed ratio is 1.

[0180] A powertrain 1010, shown in FIG. 11a, includes the conventionalengine and torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

[0181] The planetary gear set 1020 includes a sun gear member 1022, aring gear member 1024, and a planet carrier assembly 1026. The planetcarrier assembly 1026 includes a plurality of pinion gears 1027rotatably mounted on a carrier member 1029 and disposed in meshingrelationship with both the sun gear member 1022 and the ring gear member1024.

[0182] The planetary gear set 1030 includes a sun gear member 1032, aring gear member 1034, and a planet carrier assembly member 1036. Theplanet carrier assembly member 1036 includes a plurality of pinion gears1037 rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

[0183] The planetary gear set 1040 includes a sun gear member 1042, aring gear member 1044, and a planet carrier assembly member 1046. Theplanet carrier assembly member 1046 includes a plurality of pinion gears1047 rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

[0184] The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050 and 1052 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 1054, 1056, 1058 and 1059are of the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0185] The input shaft 17 is continuously connected with the planetcarrier assembly member 1026, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 1036. The sun gearmember 1022 is continuously connected with the ring gear member 1034through the interconnecting member 1070. The planet carrier assemblymember 1026 is continuously connected with the ring gear member 1044through the interconnecting member 1072. The sun gear member 1032 iscontinuously connected with the sun gear member 1042 through theinterconnecting member 1074.

[0186] The sun gear member 1022 is selectively connectable with thetransmission housing 1060 through the brake 1050. The ring gear member1024 is selectively connectable with the transmission housing 1060through the brake 1052. The ring gear member 1034 is selectivelyconnectable with the planet carrier assembly member 1046 through theclutch 1054. The ring gear member 1044 is selectively connectable withthe planet carrier assembly member 1046 through the clutch 1056. The sungear member 1042 is selectively connectable with the ring gear member1024 through the clutch 1058. The ring gear member 1024 is selectivelyconnectable with the planet carrier assembly member 1046 through theclutch 1059.

[0187] The truth table shown in FIG. 11b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the eight forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 11b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 11b. The R1/S1 value is the tooth ratiofor the planetary gear set 1020; the R2/S2 value is the tooth ratio forthe planetary gear set 1030; and the R3/S3 value is the tooth ratio forthe planetary gear set 1040. Also given in FIG. 11b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0188] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1030 and 1040. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1030. Thenumerical values of the second, fifth, sixth and seventh forward speedratios are determined utilizing the ring gear/sun gear tooth ratios ofthe planetary gear sets 1020 and 1030. The numerical values of the thirdand eighth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1020, 1030 and1040. The numerical value of the fourth forward speed ratio is 1.

[0189] A powertrain 1110, shown in FIG. 12a, has a conventional engineand torque converter 12, a planetary transmission 1114, and theconventional final drive mechanism 16. The planetary transmission 1114includes a planetary gear arrangement 1118 which is connected with theengine and torque converter 12 through the input shaft 17 and with thefinal drive mechanism 16 through the output shaft 19. The planetary geararrangement 1118 includes three planetary gear sets 1120, 1130 and 1140.

[0190] The planetary gear set 1120 includes a sun gear member 1122, aring gear member 1124, and a planet carrier assembly 1126. The planetcarrier assembly 1126 includes a plurality of pinion gears 1127rotatably mounted on a carrier member 1129 and disposed in meshingrelationship with both the sun gear member 1122 and the ring gear member1124.

[0191] The planetary gear set 1130 includes a sun gear member 1132, aring gear member 1134, and a planet carrier assembly member 1136. Theplanet carrier assembly member 1136 includes a plurality of intermeshingpinion gears 1137 that are rotatably mounted on a carrier member 1139and disposed in meshing relationship with both the sun gear member 1132and the ring gear member 1134.

[0192] The planetary gear set 1140 includes a sun gear member 1142, aring gear member 1144, and a planet carrier assembly member 1146. Theplanet carrier assembly member 1146 includes a plurality of pinion gears1147 rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

[0193] The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150 and 1152 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 1154, 1156, 1158 and 1159are of the rotating-type torque-transmitting mechanisms, commonly termedclutches.

[0194] The input shaft 17 is continuously connected with the planetcarrier assembly member 1146, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 1126. The sun gearmember 1122 is continuously connected with the sun gear member 1132through the interconnecting member 1170. The ring gear member 1124 iscontinuously connected with the sun gear member 1142 through theinterconnecting member 1172. The ring gear member 1134 is continuouslyconnected with the planet carrier assembly member 1146 through theinterconnecting member 1174.

[0195] The ring gear member 1124 is selectively connectable with thetransmission housing 1160 through the brake 1150. The ring gear member1144 is selectively connectable with the transmission housing 1160through the brake 1152. The sun gear member 1132 is selectivelyconnectable with the ring gear member 1144 through the clutch 1154. Thering gear member 1124 is selectively connectable with the planet carrierassembly member 1136 through the clutch 1156. The planet carrierassembly member 1136 is selectively connectable with the ring gearmember 1134 through the clutch 1158. The planet carrier assembly member1136 is selectively connectable with the ring gear member 1144 throughthe clutch 1159.

[0196] The truth table shown in FIG. 12b describes the engagementsequence and engagement combinations utilized with the present familymember to provide a reverse drive ratio and seven forward speed ratios.The truth table of FIG. 12b also provides a set of example numbers thatcan be established in the planetary gear arrangement 1118 utilizing thering gear/sun gear tooth ratios. The R1/S1 value is the ring gear/sungear tooth ratio of the planetary gear set 1120; the R2/S2 value is thering gear/sun gear tooth ratio of the planetary gear set 1130; and theR3/S3 value is the ring gear/sun gear tooth ratio of the planetary gearset 1140.

[0197] The chart of FIG. 12b describes the ratio steps between adjacentforward speed ratios for a seven-speed transmission. These step ratiosare established utilizing the example speed ratios given in the truthtable. As also shown in the truth table, the torque-transmittingmechanism 1150 can remain engaged through the neutral condition, therebysimplifying the forward/reverse interchange.

[0198] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1120 and 1130. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1120. Thenumerical values of the second, sixth and seventh forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1120 and 1140. The numerical values of the third andfifth forward speed ratios are determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1120, 1130 and 1140. Thenumerical value of the fourth forward speed ratio is 1.

[0199] A powertrain 1210, shown in FIG. 13a, includes the conventionalengine and torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

[0200] The planetary gear set 1220 includes a sun gear member 1222, aring gear member 1224, and a planet carrier assembly 1226. The planetcarrier assembly 1226 includes a plurality of pinion gears 1227rotatably mounted on a carrier member 1229 and disposed in meshingrelationship with both the sun gear member 1222 and the ring gear member1224.

[0201] The planetary gear set 1230 includes a sun gear member 1232, aring gear member 1234, and a planet carrier assembly member 1236. Theplanet carrier assembly member 1236 includes a plurality of pinion gears1237 rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

[0202] The planetary gear set 1240 includes a sun gear member 1242, aring gear member 1244, and a planet carrier assembly member 1246. Theplanet carrier assembly member 1246 includes a plurality of pinion gears1247 rotatably mounted on a carrier member 1249 and disposed in meshingrelationship with both the sun gear member 1242 and the ring gear member1244.

[0203] The planetary gear arrangement 1218 also includes six torquetransmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259. Thetorque transmitting mechanisms 1250 and 1252 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 1254, 1256, 1258 and 1259are rotating type torque transmitting mechanisms, commonly termedclutches.

[0204] The input shaft 17 is continuously connected with the ring gearmember 1224, and the output shaft 19 is continuously connected with thering gear member 1244. The sun gear member 1222 is continuouslyconnected with the sun gear member 1232 through the interconnectingmember 1270. The planet carrier assembly member 1226 is continuouslyconnected with the planet carrier assembly member 1246 through theinterconnecting member 1272. The ring gear member 1234 is continuouslyconnected with the ring gear member 1244 through the interconnectingmember 1274.

[0205] The planet carrier assembly member 1236 is selectivelyconnectable with the transmission housing 1260 through the brake 1250.The sun gear member 1242 is selectively connectable with thetransmission housing 1260 through the brake 1252. The planet carrierassembly member 1226 is selectively connectable with the sun gear member1222 through the clutch 1254. The planet carrier assembly member 1226 isselectively connectable with the planet carrier assembly member 1236through the clutch 1256. The ring gear member 1224 is selectivelyconnectable with the planet carrier assembly member 1236 through theclutch 1258. The ring gear member 1224 is selectively connectable withthe sun gear member 1242 through the clutch 1259.

[0206] The truth table shown in FIG. 13b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 13b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 13b. The R1/S1 value is the tooth ratiofor the planetary gear set 1220; the R2/S2 value is the tooth ratio forthe planetary gear set 1230; and the R3/S3 value is the tooth ratio forthe planetary gear set 1240. Also given in FIG. 13b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0207] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1230. The numerical values ofthe first, second, fourth and sixth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1220, 1230 and 1240. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1220 and 1230. The numerical value of the fifthforward speed ratio is 1. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 1240.

[0208] A powertrain 1310, shown in FIG. 14a, includes the conventionalengine and torque converter 12, a planetary transmission 1314, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1314 through theinput shaft 17. The planetary transmission 1314 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1314 includes a planetary gear arrangement 1318that has a first planetary gear set 1320, a second planetary gear set1330, and a third planetary gear set 1340.

[0209] The planetary gear set 1320 includes a sun gear member 1322, aring gear member 1324, and a planet carrier assembly 1326. The planetcarrier assembly 1326 includes a plurality of pinion gears 1327rotatably mounted on a carrier member 1329 and disposed in meshingrelationship with both the sun gear member 1322 and the ring gear member1324.

[0210] The planetary gear set 1330 includes a sun gear member 1332, aring gear member 1334, and a planet carrier assembly member 1336. Theplanet carrier assembly member 1336 includes a plurality of pinion gears1337 rotatably mounted on a carrier member 1339 and disposed in meshingrelationship with both the sun gear member 1332 and the ring gear member1334.

[0211] The planetary gear set 1340 includes a sun gear member 1342, aring gear member 1344, and a planet carrier assembly member 1346. Theplanet carrier assembly member 1346 includes a plurality of pinion gears1347 rotatably mounted on a carrier member 1349 and disposed in meshingrelationship with both the sun gear member 1342 and the ring gear member1344.

[0212] The planetary gear arrangement 1318 also includes six torquetransmitting mechanisms 1350, 1352, 1354, 1356, 1358 and 1359. Thetorque transmitting mechanisms 1350 and 1352 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches.The torque transmitting mechanisms 1354, 1356, 1358 and 1359 arerotating-type torque transmitting mechanisms, commonly termed clutches.

[0213] The input shaft 17 is continuously connected with the ring gearmember 1324, and the output shaft 19 is continuously connected with thering gear member 1344. The sun gear member 1322 is continuouslyconnected with the sun gear member 1332 through the interconnectingmember 1370. The planet carrier assembly member 1326 is continuouslyconnected with the planet carrier assembly member 1346 through theinterconnecting member 1372. The ring gear member 1334 is continuouslyconnected with the ring gear member 1344 through the interconnectingmember 1374.

[0214] The planet carrier assembly member 1336 is selectivelyconnectable with the transmission housing 1360 through the brake 1350.The sun gear member 1342 is selectively connectable with thetransmission housing 1360 through the brake 1352. The planet carrierassembly member 1326 is selectively connectable with the sun gear member1322 through the clutch 1354. The sun gear member 1332 is selectivelyconnectable with the ring gear member 1334 through the clutch 1356. Theplanet carrier assembly member 1326 is selectively connectable with theplanet carrier assembly member 1336 through the clutch 1358. The ringgear member 1324 is selectively connectable with the sun gear member1342 through the clutch 1359.

[0215] The truth table shown in FIG. 14b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 14b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 14b. The R1/S1 value is the tooth ratiofor the planetary gear set 1320; the R2/S2 value is the tooth ratio forthe planetary gear set 1330; and the R3/S3 value is the tooth ratio forthe planetary gear set 1340. Also given in FIG. 14b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0216] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1330. The numerical values ofthe first, second and fourth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1320, 1330 and 1340. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1320 and 1330. The numerical value of the fifthforward speed ratio is 1. The numerical value of the sixth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 1340. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1320 and 1340.

[0217] A powertrain 1410, shown in FIG. 15a, includes the conventionalengine and torque converter 12, a planetary transmission 1414, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1414 through theinput shaft 17. The planetary transmission 1414 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1414 includes a planetary gear arrangement 1418that has a first planetary gear set 1420, a second planetary gear set1430, and a third planetary gear set 1440.

[0218] The planetary gear set 1420 includes a sun gear member 1422, aring gear member 1424, and a planet carrier assembly 1426. The planetcarrier assembly 1426 includes a plurality of pinion gears 1427rotatably mounted on a carrier member 1429 and disposed in meshingrelationship with both the sun gear member 1422 and the ring gear member1424.

[0219] The planetary gear set 1430 includes a sun gear member 1432, aring gear member 1434, and a planet carrier assembly member 1436. Theplanet carrier assembly member 1436 includes a plurality of pinion gears1437 rotatably mounted on a carrier member 1439 and disposed in meshingrelationship with both the sun gear member 1432 and the ring gear member1434.

[0220] The planetary gear set 1440 includes a sun gear member 1442, aring gear member 1444, and a planet carrier assembly member 1446. Theplanet carrier assembly member 1446 includes a plurality of pinion gears1447 rotatably mounted on a carrier member 1449 and disposed in meshingrelationship with both the sun gear member 1442 and the ring gear member1444.

[0221] The planetary gear arrangement 1418 also includes six torquetransmitting mechanisms 1450, 1452, 1454, 1456, 1458 and 1459. Thetorque transmitting mechanisms 1450 and 1452 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches.The torque transmitting mechanisms 1454, 1456, 1458 and 1459 arerotating type torque transmitting mechanisms, commonly termed clutches.

[0222] The input shaft 17 is continuously connected with the planetcarrier assembly member 1426, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 1446. The planetcarrier assembly member 1426 is continuously connected with the sun gearmember 1432 through the interconnecting member 1470. The sun gear member1422 is continuously connected with the ring gear member 1444 throughthe interconnecting member 1472. The ring gear member 1434 iscontinuously connected with the sun gear member 1442 through theinterconnecting member 1474.

[0223] The sun gear member 1422 is selectively connectable with thetransmission housing 1460 through the brake 1450. The ring gear member1424 is selectively connectable with the transmission housing 1460through the brake 1452. The sun gear member 1432 is selectivelyconnectable with the planet carrier assembly member 1436 through theclutch 1454. The sun gear member 1442 is selectively connectable withthe ring gear member 1444 through the clutch 1456. The ring gear member1424 is selectively connectable with the planet carrier assembly member1436 through the clutch 1458. The planet carrier assembly member 1436 isselectively connectable with the planet carrier assembly member 1446through the clutch 1459.

[0224] The truth table shown in FIG. 15b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 15b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 15b. The R1/S1 value is the tooth ratiofor the planetary gear set 1420; the R2/S2 value is the tooth ratio forthe planetary gear set 1430; and the R3/S3 value is the tooth ratio forthe planetary gear set 1440. Also given in FIG. 15b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0225] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1430 and 1440. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1440. Thenumerical values of the second, fourth and seventh forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1420, 1430 and 1440. The numerical value of thethird forward speed ratio is 1. The numerical value of the fifth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1420 and 1440. The numerical value of thesixth forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 1420.

[0226] A powertrain 1510, shown in FIG. 16a, includes the conventionalengine and torque converter 12, a planetary transmission 1514, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1514 through theinput shaft 17. The planetary transmission 1514 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1514 includes a planetary gear arrangement 1518that has a first planetary gear set 1520, a second planetary gear set1530, and a third planetary gear set 1540.

[0227] The planetary gear set 1520 includes a sun gear member 1522, aring gear member 1524, and a planet carrier assembly 1526. The planetcarrier assembly 1526 includes a plurality of pinion gears 1527rotatably mounted on a carrier member 1529 and disposed in meshingrelationship with both the sun gear member 1522 and the ring gear member1524.

[0228] The planetary gear set 1530 includes a sun gear member 1532, aring gear member 1534, and a planet carrier assembly member 1536. Theplanet carrier assembly member 1536 includes a plurality of pinion gears1537 rotatably mounted on a carrier member 1539 and disposed in meshingrelationship with both the sun gear member 1532 and the ring gear member1534.

[0229] The planetary gear set 1540 includes a sun gear member 1542, aring gear member 1544, and a planet carrier assembly member 1546. Theplanet carrier assembly member 1546 includes a plurality of pinion gears1547 rotatably mounted on a carrier member 1549 and disposed in meshingrelationship with both the sun gear member 1542 and the ring gear member1544.

[0230] The planetary gear arrangement 1518 also includes six torquetransmitting mechanisms 1550, 1552, 1554, 1556, 1558 and 1559. Thetorque transmitting mechanisms 1550 and 1552 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches. The torque-transmitting mechanisms 1554, 1556, 1558 and 1559are rotating type torque transmitting mechanisms, commonly termedclutches.

[0231] The input shaft 17 is continuously connected with the planetcarrier assembly member 1526, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 1546. The ring gearmember 1524 is continuously connected with the sun gear member 1532through the interconnecting member 1570. The sun gear member 1522 iscontinuously connected with the ring gear member 1544 through theinterconnecting member 1572. The planet carrier assembly member 1536 iscontinuously connected with the planet carrier assembly member 1546through the interconnecting member 1574.

[0232] The ring gear member 1524 is selectively connectable with thetransmission housing 1560 through the brake 1550. The sun gear member1522 is selectively connectable with the transmission housing 1560through the brake 1552. The sun gear member 1532 is selectivelyconnectable with the sun gear member 1542 through the clutch 1554. Theplanet carrier assembly member 1546 is selectively connectable with thering gear member 1544 through the clutch 1556. The planet carrierassembly member 1526 is selectively connectable with the sun gear member1542 through the clutch 1558. The ring gear member 1534 is selectivelyconnectable with the sun gear member 1542 through the clutch 1559.

[0233] The truth table shown in FIG. 16b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 16b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 16b. The R1/S1 value is the tooth ratiofor the planetary gear set 1520; the R2/S2 value is the tooth ratio forthe planetary gear set 1530; and the R3/S3 value is the tooth ratio forthe planetary gear set 1540. Also given in FIG. 16b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0234] Those skilled in the art will recognize that the numerical valuesof the reverse and seventh forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1520,1530 and 1540. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1540. The numerical values of the second, fourth and fifthforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1520 and 1540. The numericalvalue of the third forward speed ratio is 1. The numerical value of thesixth forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 1520.

[0235] A powertrain 1610, shown in FIG. 17a, includes the conventionalengine and torque converter 12, a planetary transmission 1614, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1614 through theinput shaft 17. The planetary transmission 1614 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1614 includes a planetary gear arrangement 1618that has a first planetary gear set 1620, a second planetary gear set1630, and a third planetary gear set 1640.

[0236] The planetary gear set 1620 includes a sun gear member 1622, aring gear member 1624, and a planet carrier assembly 1626. The planetcarrier assembly 1626 includes a plurality of pinion gears 1627rotatably mounted on a carrier member 1629 and disposed in meshingrelationship with both the sun gear member 1622 and the ring gear member1624.

[0237] The planetary gear set 1630 includes a sun gear member 1632, aring gear member 1634, and a planet carrier assembly member 1636. Theplanet carrier assembly member 1636 includes a plurality of pinion gears1637 and 1638 rotatably mounted on a carrier member 1639 and disposed inmeshing relationship with both the sun gear member 1632 and the ringgear member 1634.

[0238] The planetary gear set 1640 includes a sun gear member 1642, aring gear member 1644, and a planet carrier assembly member 1646. Theplanet carrier assembly member 1646 includes a plurality of pinion gears1647 rotatably mounted on a carrier member 1649 and disposed in meshingrelationship with both the sun gear member 1642 and the ring gear member1644.

[0239] The planetary gear arrangement 1618 also includes six torquetransmitting mechanisms 1650, 1652, 1654, 1656, 1658 and 1659. Thetorque transmitting mechanisms 1650 and 1652 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches.The torque transmitting mechanisms 1654, 1656, 1658 and 1659 arerotating-type torque transmitting mechanisms, commonly termed clutches.

[0240] The input shaft 17 is continuously connected with the planetcarrier assembly member 1626, and the output shaft 19 is continuouslyconnected with the ring gear member 1634. The sun gear member 1622 iscontinuously connected with the planet carrier assembly member 1636through the interconnecting member 1670. The ring gear member 1624 iscontinuously connected with the sun gear member 1642 through theinterconnecting member 1672. The sun gear member 1632 is continuouslyconnected with the ring gear member 1644 through the interconnectingmember 1674.

[0241] The ring gear member 1634 is selectively connectable with thetransmission housing 1660 through the brake 1650. The ring gear member1624 is selectively connectable with the transmission housing 1660through the brake 1652. The planet carrier assembly member 1626 isselectively connectable with the sun gear member 1632 through the clutch1654. The sun gear member 1632 is selectively connectable with the ringgear member 1634 through the clutch 1656. The ring gear member 1634 isselectively connectable with the planet carrier assembly member 1646through the clutch 1658. The planet carrier assembly member 1646 isselectively connectable with the sun gear member 1642 through the clutch1659.

[0242] The truth table shown in FIG. 17b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 17b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 17b. The R1/S1 value is the tooth ratiofor the planetary gear set 1620; the R2/S2 value is the tooth ratio forthe planetary gear set 1630; and the R3/S3 value is the tooth ratio forthe planetary gear set 1640. Also given in FIG. 17b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0243] Those skilled in the art will recognize that the numerical valuesof the reverse and seventh forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1620,1630 and 1640. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1630. The numerical values of the second, fourth and fifthforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1620 and 1630. The numericalvalue of the third forward speed ratio is 1. The numerical value of thesixth forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 1620.

[0244] While the best modes for carrying out the invention have beendescribed in detail, those familiar with the art to which this inventionrelates will recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

What is claimed is:
 1. A family of transmissions wherein each familymember comprises: an input shaft; an output shaft; first, second andthird planetary gear sets each having first, second and third members;said input shaft being continuously interconnected with at least onemember of said planetary gear sets, said output shaft being continuouslyinterconnected with another member of said planetary gear sets; a firstinterconnecting member continuously interconnecting said first member ofsaid first planetary gear set and said first member of said secondplanetary gear set; a second interconnecting member continuouslyinterconnecting said second member of said first planetary gear set andsaid first member of said third planetary gear set; a thirdinterconnecting member continuously interconnects said second member ofsaid second planetary gear set with said second member of said thirdplanetary gear set; a first torque-transmitting mechanism selectivelyinterconnecting a stationary transmission housing with a member of saidfirst or second planetary gear sets or one of said first, second andthird interconnecting members; a second torque-transmitting mechanismselectively interconnecting said stationary transmission housing with amember of said first, second or third planetary gear sets; a thirdtorque-transmitting mechanism selectively interconnecting a member ofsaid first planetary gear set or one of said first, second and thirdinterconnecting members with said input shaft, said output shaft or amember of said second or third planetary gear sets; a fourthtorque-transmitting mechanism selectively interconnecting a member ofsaid second planetary gear set or one of said first, second and thirdinterconnecting members with said input shaft, said output shaft, or amember of said first or third planetary gear sets; a fifthtorque-transmitting mechanism selectively interconnecting a member ofsaid third planetary gear set with another member of said first, secondor third planetary gear sets; and a sixth torque-transmitting mechanismselectively interconnecting a member of the first, second or thirdplanetary gear sets with another member of said first, second or thirdplanetary gear sets; said torque-transmitting mechanisms being engagedin combinations of two to establish at least seven forward speed ratiosand a reverse speed ratio between said input shaft and said outputshaft.
 2. The family of transmissions defined in claim 1, wherein saidfirst and second and torque-transmitting mechanisms comprise brakes. 3.The family of transmissions defined in claim 1, wherein said third,fourth, fifth and sixth torque-transmitting mechanisms compriseclutches.
 4. The family of transmissions defined in claim 1, whereinplanet carrier assembly members of each of said planetary gear sets areof the single-pinion type.
 5. The family of transmissions defined inclaim 1, wherein at least one planet carrier assembly member of saidplanetary gear sets is of the double-pinion type.
 6. A family oftransmissions having a plurality of family members wherein each familymember comprises: an input shaft; an output shaft; a planetary geararrangement having first, second and third planetary gear sets, eachplanetary gear set having first, second and third members; said inputshaft being continuously interconnected with at least one member of oneof said planetary gear sets, said output shaft being continuouslyinterconnected with another member of said planetary gear sets; a firstinterconnecting member continuously interconnecting said first member ofsaid first planetary gear set and said first member of said secondplanetary gear set; a second interconnecting member continuouslyinterconnecting said second member of said first planetary gear set andsaid first member of said third planetary gear set; a thirdinterconnecting member continuously interconnecting said second memberof said second planetary gear set with said second member of said thirdplanetary gear set; and two brakes and four clutches for selectivelyinterconnecting said members of said planetary gear sets with said inputshaft, said output shaft, said transmission housing, said first, secondand third interconnecting members, or other members of said planetarygear sets, said two brakes and four clutches being engaged incombinations of two to establish at least seven forward speed ratios andone reverse speed ratio between said input shaft and said output shaft.7. The family of transmissions defined in claim 6, wherein a first ofsaid two brakes is operable for selectively interconnecting saidstationary transmission housing with a member of said first or secondplanetary gear sets, or one of said first, second and thirdinterconnecting members.
 8. The family of transmissions defined in claim6, wherein a second of said two brakes is operable for selectivelyinterconnecting said stationary transmission housing with a member ofsaid first, second or third planetary gear sets.
 9. The family oftransmissions defined in claim 6, wherein a first of said four clutchesis selectively operable for interconnecting a member of said firstplanetary gear set or one of said first, second and thirdinterconnecting members with said input shaft, said output shaft or amember of said second or third planetary gear sets.
 10. The family oftransmissions defined in claim 6, wherein a second of said four clutchesis selectively operable for interconnecting a member of said secondplanetary gear set or one of said first, second and thirdinterconnecting members with said input shaft, said output shaft, or amember of said first or third planetary gear sets.
 11. The family oftransmissions defined in claim 6, wherein a third of said four clutchesis selectively operable for interconnecting a member of said thirdplanetary gear set with another member of said first, second or thirdplanetary gear sets.
 12. The family of transmissions defined in claim 6,wherein a fourth of said four clutches selectively interconnects amember of said first, second and third planetary gear sets with anothermember of said first, second and third planetary gear sets.
 13. Thefamily of transmissions in claim 6, wherein planet carrier assemblymembers of each of said planetary gear sets are of the single-piniontype.
 14. The family of transmissions in claim 6, wherein at least oneplanet carrier assembly member of said planetary gear sets is of thedouble-pinion type.